The present invention relates generally to a trailer tipper or dumper for dumping the contents from a trailer containing a dumpable material, and more particularly to an improved portable tipper and an improved method of removing the contents from such a trailer. For example, such a tipper and method may be used to dump garbage from trailers at a landfill site.
Other portable trailer dumpers or tippers have been used to dump garbage from semi-truck haulable trailers at commercial dumps. One known tipper includes a haulable frame having a front end hitchable to a semi-truck for moving the tipper between different dumping locations.
This known tipper includes an upwardly pivoting deck attached to the frame back end. The deck has an upwardly extending backstop adjacent the back end of the deck to retain a trailer during tipping. Two hydraulic actuators are mounted to the frame and underside of the deck to push the deck from a lowered position in contact with the frame upwardly to a raised position for dumping the contents of the trailer. To power the hydraulic actuators, the tipper includes a hydraulic power unit mounted to the frame underside midway between the frame front and back ends.
In a lowered position adjacent the frame, the deck is substantially level at a height of nearly eleven feet above the ground surface upon which the tipper is located. To bridge this distance, the tipper has a detachable ramp extending downward from the frame front end. The frame also includes a permanently mounted intermediate ramped section for bridging a gap between the deck and the detachable ramp.
This known tipper includes front and rear stabilizer wings extending outwardly from the frame sides, with each wing having a ground-engaging float with screw-type height adjustment means. The stabilizers are adjustable to level the deck. The stabilizer floats are removed from the stabilizer wings and the wings are folded back against the frame for towing the tipper between dumping locations. To ready the tipper for moves between locations at a given site, the stabilizer floats and ramp must be removed and placed on top of the tipper.
To use this known tipper, a driver backs a trailer containing a dumpable material onto the detachable ramp, across the intermediate ramp and onto the deck until the trailer engages the deck backstop. To unhook the trailer for dumping, the driver gets out of the truck cab, which is nearly as high as the deck (approximately eleven feet above the ground surface). Any fall from such a height may seriously injure the driver. Thus, this tipper requires hand rails and barriers along the edges of the ramps and deck.
The basic manufacturing costs of such hand rails and barriers increase the initial cost of the known tipper. Furthermore, there are the labor costs associated with disassembling and reassembling the hand rails and barriers when moving the tipper from one location at a dump site to another location at the same dump site.
Tippers are inherently susceptible to side loading when the deck is elevated to dump a trailer. For example, side loading may occur when a strong cross wind blows against a side of a trailer during dumping. The deck acts as a moment arm and side loading force applies a torque to the frame. To prevent frame deformation by twisting during such side loading, this known frame requires great amounts of reinforcing steel and larger and heavier steel members in the frame. The additional reinforcing steel increases tipper manufacturing costs, as well as making the tipper heavy to haul, which increases fuel costs associated with moving the tipper.
Thus, a need exists for an improved trailer tipper and method for dumping the contents from a trailer containing a dumpable material, which is not susceptible to the above limitations and disadvantages.